My personal suspicion, since cryonic suspension is involved, is that a time-gapped release of people in 111 happens, either by accident, or design.
Whatever the story mechanic behind such, the spouse and child are compelled to leave 111, perhaps even leaving (an undated, or corrupted) message/video/holotape for you to find.
You find the message with no clue how long ago it may have been left, and strike out into the wasteland on the trail of your spouse and child.
Eventually, you find the corpse/skeleton of your spouse, and it's a corpse/skeleton so you still can't tell how old your spouse was when they died (still masking how much time has passed), but, there's clues to find your child.
Eventually you find your child, but, your child is all grown up.
Several possibilities are open here, some of which could be:
1. Your child is an advlt major faction leader character on a moral/karma path you have the choice to help or fight against.
2. Your child is an advlt major faction leader character on a moral/karma path you have the choice to convince to change, and then either help/save or fight against/kill.
3. Your child is an advlt major faction character, but not a leader, only a follower where 1, or 2 above then apply.
4. Your child is imprisoned or held captive by a major faction for crimes you may have to judge them on, and decide how to deal with.
5. Same as 4, but, child plays innocent, and when freed double-crosses/betrays you, and escapes and you have to decide how deal with it (quest continuation)
There's sundry more, of course, and many the variation, but the main gist will likely present a moral conflict over saving your child vs. some larger ideal.